HR: 14:55h
AN: SM13E-06    [Abstracts]
TI: Magnetospheric {ULF} Activity as a Function of Solar Wind Conditions: Toward a Quantitative Model of Radial Diffusion in the Magnetosphere
AU: * Elkington, S R
EM: scot.elkington@lasp.colorado.edu
AF: Laboratory for Atmospheric and Space Physics, University of Colorado, 1234 Innovation Drive, Boulder, CO 80303, United States
AU: Huang, C
EM: hcl@bu.edu
AF: Boston University, Astronomy Department, 725 Commonwealth Ave Rm 514, Boston, MA 02215, United States
AU: Chan, A A
EM: aac@rice.edu
AF: Rice University, Department of Physics and Astronomy, POB 1892, Houston, TX 77251, United States
AU: Mann, I R
EM: imann@phys.ualberta.edu
AF: University of Alberta, Department of Physics, Mailstop #615, Edmonton, AB T6G 2G7, Canada
AU: Rae, I J
EM: jrae@phys.ualberta.ca
AF: University of Alberta, Department of Physics, Mailstop #615, Edmonton, AB T6G 2G7, Canada
AB: Magnetospheric ULF waves, with frequencies in the mHz range, are known to efficiently energize and transport relativistic electrons in the radiation belts through resonant interactions leading to enhanced rates of radial diffusion. However, the global occurrence and physical characteristics of the waves driving the transport, and the resulting rates of radial diffusion, are not well-characterized in terms of the solar wind conditions responsible for the ULF activity. In this effort we drive global MHD simulations of the magnetosphere using an idealized set of solar wind conditions, based on statistical characterizations of the solar wind pressure (and its variations) as a function of solar wind velocity. The simulated ULF wave distributions are analyzed as a function of radial position and global mode structure within the magnetosphere. By applying interpolation techniques to the resulting wave distributions, we create 'synthetic' maps of ULF activity as a function of solar wind velocity. We compare the synthetic rates of radial diffusion to commonly-used empirical diffusion coefficients, and to those derived from simulations driven by `real' solar wind conditions (observed by upstream solar wind monitors) representing CME- and CIR-driven storms. These comparisons are used to investigate the feasibility of using synthetic, solar wind-driven ULF maps to quantify rates of radial diffusion for real magnetospheric events.
DE: 7807 Charged particle motion and acceleration
DE: 7836 MHD waves and instabilities (2149, 2752, 6050)
DE: 7845 Particle acceleration
DE: 7867 Wave/particle interactions (2483, 6984)
DE: 7984 Space radiation environment
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting